1. Field of the Invention
The present invention is directed to a urethral catheter stent which uses a double J arrangement. The double J is basically a flexible stent for irrigation with a hook at each end forming a J at each end. The present invention is directed to an improved stent of the double J type which provides for the ability of the inserting physician to controllably rotate the stent during insertion, and, also, enables controlled reentry into the stent for various purposes.
2. Prior Art Statement
Various types of catheters have been available for many decades and are important to the survival of some patients. For example, U.S. Pat. No. 2,393,003 describes a kidney catheter wherein a flexible rod made of metal or any suitable material is used to stiffen a otherwise soft catheter to enable a urologist to direct the catheter up into the kidney. This particular patent teaches the use of a hook on the handle of a rod which attaches to a tongue at the end of the catheter so as to maintain it in a stretched position during insertion, i.e., to prevent it from sliding off or folding or otherwise creating difficulties during insertion.
Ureteral catheter stents were developed as drainage tubes to bypass urethral obstructions or ureterovaginal fistulas so as to maintain urinary drainage. Prior art stents have been made of flexible materials and are usually hollow elongated members with irrigation orifices throughout all or part of the length of the stent. Stents may be fully open ended at both ends or open at only one end, depending upon the method of insertion and ultimate purpose. U.S. Pat. No. 4,212,304 to Roy Finney describes a catheter which has proximal and distal ends which are in the form of hooks. These hooks are sometimes referred to as J stents or double J stents. These types of stents are straightened for introduction into the body passage by the insertion of a wire stylet into the lumen of the stent and the stent is provided with some sort of indicating means to show the direction of the proximal hook so that the surgeon inserting same will know approximately the direction of the proximal hook when the stylet is removed so that proper placement is enhanced.
U.S. Pat. No. 4,787,884 to Jay Goldberg describes a dual wire guide system for inserting ureteral stents and particularly the double J type stents. In this patent, the pusher wires open at both ends and sized to fit into the lumen of the stent. The leading end of the pusher wire has a diameter greater than the reduced opening in the stent and the guide wire is sized to fit within the lumen of the pusher wire and has a leading end which is smaller in diameter than the reduced opening of the stent. The retaining member keeps the leading end of the guide wire from leaving the lumen of the pusher wire when an obstruction is encountered in the ureter, the retaining member is disengaged and the leading end of the guide wire is passed through the reduced opening and maneuvered passed the obstruction. The pusher wire and stent then can be advanced over the guide wire passed the obstruction.
Notwithstanding the prior art, it is believed that the present invention improved double J stent affording the user the ability to control the rotation or movement of the stent during insertion both with accuracy and with ease as well as assuring the opportunity for future use of the stent, is neither taught nor rendered obvious in the prior art.